Ancient Prehistoric Monster [LOOK]
Ohio’s prehistoric monster a 360-million-year-old sea creature named ” Dunkleosteus terrelli “, one of the largest ancient fish in history, was now found have half of its original length, but was still very chunky, according to a new study.
Nicknamed “Dunk,” Dunkleosteus terrelli was a super predator of the Devonian period (419 million to 358 million years ago). This massive, armored fish, which swam in the oceans that filled modern-day Ohio, had jaws that could close with 8,000 pounds of force. In 1870, fossils of this creature were found near Cleveland on the shores of Lake Erie and, today, the largest specimen is held in the collections of the Cleveland Museum of Natural History.
It had a bony, armored skull attached to a cartilage skeleton, unlike modern fish, which either have cartilage or bone skeletons. Its skull was terrifying it stood nearly 3 feet tall.
It was only their skulls that fossilized, so early researchers extrapolated “Dunkleosteus terrelli” size based on the relationship between a shark’s skull size and its body length. Although it became Ohio’s official prehistoric fish for the next 150 years, Dunkleosteus terrelli still received little scientific attention despite becoming a local paleontology icon.
Russell Engelman, a doctoral student at Case Western University in Cleveland, Ohio, was unable to conduct his normal lab research during the pandemic as many restrictions were implemented and a whole world of crazy was going on at the time. Even so Russell decided to go to the Cleveland Museum of Natural History to think about some research ideas that could help him uncover more about this prehistoric creature.
While inspecting some of the specimens from D. Terrelli available to him he came across some an issue.
“Everything in biology is influenced by body size,” Russell said. “I tried using some of the old measurements, and biologically, they just didn’t make sense.”
His reconstructions required strange, unrealistic body proportions that looked nothing like the original drawings of D. Terrelli, so Engelman was unable to reconcile the skull with the 30-foot body. At that point, he found out how the original researchers determined D. Terrelli’s size, which revealed the real problem.
“I went back through the literature, and it turned out that most previous authors who had talked about this were basically just eyeballing it,” Engelman said.
Engeman measured the dimensions of different fish skulls and compared them with their body proportions. He found that skull size and shape are highly correlated with body size. When applied to D. Terrelli, this analysis ruled out all extreme size estimates. Instead of being 30 feet long, D. terrelli was likely no longer than 13 feet long.
Engelman’s research looked into several details, and what seemed to be the key factor was the height compared to width of the skull. Creatures with a head of more extended proportions were found to have longer bodies, while those with shorter skulls remained compact. D. terrelli was distinct for its uncharacteristically small cranium which implied a shorter, wider body, similar to that of a tuna rather than a shark. Despite the initial setback, Engelman is enthused by the outcome. His experience serves as an example that even paleoichthyologists can overestimate their finds sometimes.
Sources: Livescience
